Universal phonon softening in the pseudogap state of Tl${}_2$Ba${}_2$Ca${}_{n-1}$Cu${}_n$O${}_{2n+4+\delta }$

Jia-Wei Hu, Kai Zhang, Yong-Chang Ma +5

Exploring the origin of the pseudogap is important for the understanding of superconductivity in cuprates. Here we report a systematical experimental study on the phonon vibrationa…